Left ventricle assist devices (LVAD's) are mechanical devices that are implanted into a patient's body to assist the function of the patient's heart. These devices often remain in place for an extended period of time that may approach the end of an LVAD's useful life. Currently, it is difficult to assess the mechanical state of an LVAD without accessing the LVAD using surgical procedures, which can be expensive, painful, and prone to risk.
Dr. Mark A. Slaughter et al. recently published an article on various techniques for utilizing acoustic signatures to identify the end of life of a particular type of LVAD, the Heartmate XVE. (This article is included as part of this disclosure—See Appendix A.) However, the apparatus described in the Slaughter article appears to be bulky, cumbersome, and may be prone to false alarms that are generated due to noise from sources within the patient's body other than the LVAD. Accordingly, there is a need for improved, more reliable, non-invasive procedures for assessing the mechanical state of LVAD's and other mechanical devices that are implanted within a patient's body.